"arranger of sexual liaisons, one who supplies another with the means of gratifying lust," 1520s, "procurer, pimp," from Middle English Pandare (late 14c.), used by Chaucer ("Troylus and Cryseyde"), who borrowed it from Boccaccio (who had it in Italian form Pandaro in "Filostrato") as name of the prince (Greek Pandaros), who procured the love of Cressida (his niece in Chaucer, his cousin in Boccaccio) for Troilus. The story and the name are medieval inventions. Spelling influenced by agent suffix -er.